Science has measured how dinner affects sleep, and the result explains why you wake up craving sugar

A University of Granada study found that heavy dinners high in fat, fried foods, alcohol, and large portions were linked to poorer sleep.

By contrast, complex carbs, oily fish, and tryptophan-rich foods were associated with better rest in adults with obesity monitored for 14 days.

A bad night’s sleep was also tied to a sweeter, lower-fiber breakfast the next day, suggesting a diet-sleep cycle.

The findings, published in the European Journal of Nutrition, highlight how dinner choices may affect sleep quality and next-day sugar cravings.